Businesses and consumers use a wide variety of fixed and mobile wireless terminals, including cell phones, pagers, Personal Communication Services (PCS) systems, and fixed wireless access devices (i.e., vending machine with cellular capability). Wireless service providers continually try to create new markets for wireless devices and expand existing markets by making wireless devices and services cheaper and more reliable. The price of wireless devices has decreased to the point where these devices are affordable to nearly everyone.
A conventional public wide area network (WAN), such as a CDMA cellular network, covers a large geographical area (on the order of 1 to 100 plus square miles), but has a relatively low bit-rate between each mobile station and each base station. These public wireless networks use regulated portions of the radio spectrum and are shared by many users. The infrastructure costs of public wireless networks are relatively high due to the size and complexity of the base station equipment.
Newer wireless networks, such as CDMA2000-EV-DO/DV networks, offer higher bit-rates (on the order to 2.4 MBps) and enhanced data services, such as web browsing. These networks pack many users into a relatively small portion of the regulated spectrum. Other types of radio networks, such as wireless local area networks (WLANs), try to improve spectral efficiency and to increase bit-rates by using unregulated frequencies and smaller coverage areas. For example, an IEEE 802.xx wireless LAN (i.e., a WI-FI network) may transmit at speeds up to 11 MBps in Direct Sequence Spread Spectrum (DSSS) mode or at speeds up to 54 MBps in Orthogonal Frequency Division Multiplexing (OFDM) mode.
An access point (or base station) in an IEEE 802.xx (e.g., IEEE 802.11) network may cover an area only a few hundred feet in diameter. Each access point is connected to the core network (e.g., Internet). In order to cover the same geographical area as a base station of a public wireless network, a large number of IEEE 802.xx network access points and a large wireline back haul network are required. Thus, there are always tradeoffs between and among the coverage areas, the maximum bit-rates, and the costs of different types of wireless networks.
In order to reduce the number of wireless devices a consumer must carry, equipment vendors have developed dual mode transceivers that allow a user to access both public wireless (e.g., CDMA2000) networks and wireless LANs. However, the usefulness of these devices because it is not technically feasible to perform reliably a seamless handoff between a CDMA2000 network and a wireless LAN. Thus, if a user is mobile, the user may repeatedly drop data sessions with one type of network and be forced to search for and access another type of network.
Also, there is no control mechanism that can efficiently distribute traffic loads between CDMA2000 networks and wireless LANs. A user in a CDMA2000 wireless network may have difficulty browsing websites and receiving e-mail during peak traffic conditions. At the same time, the user could easily access a lightly loaded 802.11 wireless LAN. There currently is no mechanism that can cause the user's mobile station to automatically handoff from the busy CDMA2000 wireless network to the underutilized 802.11 wireless LAN.
Therefore, there is a need in the art for an improved wireless network architecture that overcomes the limitations of the above-described conventional wireless networks. In particular, there is a need for a system and method that provides a handoff capability between CDMA2000 networks and wireless LANs. More particularly, there is a need for a wireless network architecture that uses this handoff capability to distribute data traffic between CDMA2000 networks and wireless LANs.